diff --git a/core/api/current.txt b/core/api/current.txt
index 2b5075d..8224a75 100644
--- a/core/api/current.txt
+++ b/core/api/current.txt
@@ -39222,6 +39222,7 @@
     field public static final String KEY_GSM_ROAMING_NETWORKS_STRING_ARRAY = "gsm_roaming_networks_string_array";
     field public static final String KEY_HAS_IN_CALL_NOISE_SUPPRESSION_BOOL = "has_in_call_noise_suppression_bool";
     field public static final String KEY_HIDE_CARRIER_NETWORK_SETTINGS_BOOL = "hide_carrier_network_settings_bool";
+    field public static final String KEY_HIDE_ENABLE_2G = "hide_enable_2g_bool";
     field public static final String KEY_HIDE_ENHANCED_4G_LTE_BOOL = "hide_enhanced_4g_lte_bool";
     field public static final String KEY_HIDE_IMS_APN_BOOL = "hide_ims_apn_bool";
     field public static final String KEY_HIDE_LTE_PLUS_DATA_ICON_BOOL = "hide_lte_plus_data_icon_bool";
diff --git a/core/api/system-current.txt b/core/api/system-current.txt
index ad86788..7066f79 100644
--- a/core/api/system-current.txt
+++ b/core/api/system-current.txt
@@ -10234,6 +10234,7 @@
     field public static final String ACTION_SIM_CARD_STATE_CHANGED = "android.telephony.action.SIM_CARD_STATE_CHANGED";
     field public static final String ACTION_SIM_SLOT_STATUS_CHANGED = "android.telephony.action.SIM_SLOT_STATUS_CHANGED";
     field public static final int ALLOWED_NETWORK_TYPES_REASON_CARRIER = 2; // 0x2
+    field public static final int ALLOWED_NETWORK_TYPES_REASON_ENABLE_2G = 3; // 0x3
     field public static final int ALLOWED_NETWORK_TYPES_REASON_POWER = 1; // 0x1
     field public static final int ALLOWED_NETWORK_TYPES_REASON_USER = 0; // 0x0
     field public static final int CALL_WAITING_STATUS_DISABLED = 2; // 0x2
diff --git a/core/java/android/provider/Telephony.java b/core/java/android/provider/Telephony.java
index 9cb76c1..753abea 100644
--- a/core/java/android/provider/Telephony.java
+++ b/core/java/android/provider/Telephony.java
@@ -5284,7 +5284,8 @@
          * which network types are allowed for
          * {@link TelephonyManager#ALLOWED_NETWORK_TYPES_REASON_USER},
          * {@link TelephonyManager#ALLOWED_NETWORK_TYPES_REASON_POWER},
-         * {@link TelephonyManager#ALLOWED_NETWORK_TYPES_REASON_CARRIER}.
+         * {@link TelephonyManager#ALLOWED_NETWORK_TYPES_REASON_CARRIER},
+         * {@link TelephonyManager#ALLOWED_NETWORK_TYPES_REASON_ENABLE_2G}.
          * <P>Type: TEXT </P>
          *
          * @hide
diff --git a/telephony/java/android/telephony/CarrierConfigManager.java b/telephony/java/android/telephony/CarrierConfigManager.java
index 217570e..464d375 100644
--- a/telephony/java/android/telephony/CarrierConfigManager.java
+++ b/telephony/java/android/telephony/CarrierConfigManager.java
@@ -4268,6 +4268,14 @@
     public static final String KEY_STORE_SIM_PIN_FOR_UNATTENDED_REBOOT_BOOL =
             "store_sim_pin_for_unattended_reboot_bool";
 
+     /**
+     * Determine whether "Enable 2G" toggle can be shown.
+     *
+     * Used to trade privacy/security against potentially reduced carrier coverage for some
+     * carriers.
+     */
+    public static final String KEY_HIDE_ENABLE_2G = "hide_enable_2g_bool";
+
     /** The default value for every variable. */
     private final static PersistableBundle sDefaults;
 
@@ -4825,6 +4833,7 @@
         sDefaults.putStringArray(KEY_ALLOWED_INITIAL_ATTACH_APN_TYPES_STRING_ARRAY,
                 new String[]{"ia", "default", "ims", "mms", "dun", "emergency"});
         sDefaults.putBoolean(KEY_STORE_SIM_PIN_FOR_UNATTENDED_REBOOT_BOOL, true);
+        sDefaults.putBoolean(KEY_HIDE_ENABLE_2G, false);
     }
 
     /**
diff --git a/telephony/java/android/telephony/TelephonyManager.java b/telephony/java/android/telephony/TelephonyManager.java
index 1ff450a..26fcf5e 100644
--- a/telephony/java/android/telephony/TelephonyManager.java
+++ b/telephony/java/android/telephony/TelephonyManager.java
@@ -8224,7 +8224,8 @@
     @IntDef({
             ALLOWED_NETWORK_TYPES_REASON_USER,
             ALLOWED_NETWORK_TYPES_REASON_POWER,
-            ALLOWED_NETWORK_TYPES_REASON_CARRIER
+            ALLOWED_NETWORK_TYPES_REASON_CARRIER,
+            ALLOWED_NETWORK_TYPES_REASON_ENABLE_2G
     })
     @Retention(RetentionPolicy.SOURCE)
     public @interface AllowedNetworkTypesReason {
@@ -8261,6 +8262,14 @@
     public static final int ALLOWED_NETWORK_TYPES_REASON_CARRIER = 2;
 
     /**
+     * To indicate allowed network type change is requested by the user via the 2G toggle.
+     *
+     * @hide
+     */
+    @SystemApi
+    public static final int ALLOWED_NETWORK_TYPES_REASON_ENABLE_2G = 3;
+
+    /**
      * Set the allowed network types of the device and
      * provide the reason triggering the allowed network change.
      * This can be called for following reasons
@@ -8269,6 +8278,8 @@
      * <li>Allowed network types control by power manager
      * {@link #ALLOWED_NETWORK_TYPES_REASON_POWER}
      * <li>Allowed network types control by carrier {@link #ALLOWED_NETWORK_TYPES_REASON_CARRIER}
+     * <li>Allowed network types control by the user-controlled "Allow 2G" toggle
+     * {@link #ALLOWED_NETWORK_TYPES_REASON_ENABLE_2G}
      * </ol>
      * This API will result in allowing an intersection of allowed network types for all reasons,
      * including the configuration done through other reasons.
@@ -8358,6 +8369,7 @@
             case TelephonyManager.ALLOWED_NETWORK_TYPES_REASON_USER:
             case TelephonyManager.ALLOWED_NETWORK_TYPES_REASON_POWER:
             case TelephonyManager.ALLOWED_NETWORK_TYPES_REASON_CARRIER:
+            case TelephonyManager.ALLOWED_NETWORK_TYPES_REASON_ENABLE_2G:
                 return true;
         }
         return false;